This invention relates to a thermally responsive valve assembly and more particularly to such a valve assembly which in one embodiment is specifically adapted to be positioned in heat-transfer relation with an object (e.g., an automobile engine block) to open and close the valve upon increase or decrease in temperature, and which in another embodiment smoothly controls the flow rate of fluid through the valve upon increase or decrease of the temperature thereof.
The thermally responsive valve assembly of this invention is particularly adapted for use in an emission gas recirculation control system, such as used on automotive engines, to vent or block a vacuum system upon the engine attaining a desired operating temperature. The valve of this invention may be used in place of a solenoid valve which requires an electric circuit for energization and which is more expensive.